A sheet post-processing apparatus configured to apply post-processing to a sheet is connected to an image forming apparatus such as an MFP (Multi-Functional Peripheral), a copying machine, or a printer. The image forming apparatus forms an image on the sheet and discharges the sheet. The sheet post-processing apparatus executes post-processing such as sorting or stapling on the sheet.
Sheets supplied to the sheet post-processing apparatus are cut sheets (cut paper). The cut sheets have sheet sizes. The sheet sizes are classified into plural kinds of standard sizes according to sheet widths and sheet lengths.
The sheet widths indicate sheet dimensions in a direction orthogonal to a sheet conveying direction in which the sheets are conveyed. The sheet lengths indicate sheet dimensions in the sheet conveying direction.
There are various standard sizes such as ISO (International Standard) A3 and A4, LD (ledger), LT (letter), LG (legal), and tabloid. The tray length of a paper discharge tray is adjusted to any one of all the kinds of standard sizes.
In some case, a long sheet having sheet length of, for example, 1200 mm is used for hanger displays in vehicles.
When the image forming apparatus forms an image on the long sheet, the long sheet is set on a manual feed tray. The sheet post-processing apparatus conveys the long sheet to an upper paper discharge tray through a space on the upper side.
The image forming apparatus prints the long sheet (a special sheet) and outputs the long sheet to the sheet post-processing apparatus. In this case, the size of the long sheet is not a size of a sheet stacked on a fixed tray or a movable tray. Therefore, the sheet post-processing apparatus directly drops and outputs the long sheet onto the floor surface.
However, when the printed long sheet is dropped and output onto the floor surface from the sheet post-processing apparatus, the printed long sheet or an image printed on the long sheet is soiled or the long sheet is scratched.
When a tray having tray length enough for stacking the long sheet is provided in the sheet post-processing apparatus, the size of the sheet post-processing apparatus becomes excessively large. The tray causes a problem in setting the image forming apparatus and the sheet post-processing apparatus.
It is difficult to stack the long sheet on the fixed tray and the movable tray without bending the long sheet and without scratching the long sheet.
It is necessary to provide a dedicated member for conveying the long sheet in the sheet post-processing apparatus. In other words, it is necessary to separately provide a component in the sheet post-processing apparatus.